I have a room that is 1440 cubic feet. I am using a C.A.P co2 generator keeping the room constant at 1500ppm and because it produces heat, my temp goes up to about 89-92 degrees. I am currently in veg and I leave the co2 on for 12 hours of my light cycle and turn it off for the other 6 hours which happen to be the hottest part of the day. The temps in the room are: 85-92 for the first 12 hours when the co2 is on 75-80 for the remaining 6 hours of the light cycle 68-73 during the 6 hours of darkness My questions are as follows: 1) What temp should the room be when using co2? 2) Is there a problem with running it 12 hours out of the 18 hour veg cycle? 3)Is there any potential problem with my temperatures?
co2 increases the ability of the plant to 'sweat' because it lets the stomata stay open. if u have proper watering and no other issues, those temps that u listed are more than fine. maybe once summer hits and the temps go up, u can try to limit ur co2 burning to mornings. 1500ppm is desired but 1000ppm is also decent. that is a decent enough size room where the plants wont use up 500ppm. id say with CO2 ppm over 700, keep the temp under 95. make sure that ur nighttime ppm are not too much over 700. this can slow down ur nightime growth. remember that plants use O2 and stored sugars all the time to do the actual growth, but during the day the plants make more sugars than they can use during the day and use them at night. so during this respiration that the plant does, if the CO2 is very hi, the plant can get choked with co2. during the day, it can suck it up, at night, it cannot.
using co2 above 85* is totaly wasting it.and temps that high slow growth to a crawl no matter what you do...
id have to agere with scary visionary - these temps are WAY TOO HIGH. Let me suggest this if you are not already doing this - when CO2 is on, your exhaust fan (hope you are using one) should be off, or you will just be sucking the CO2 out of the room. Intermittently switch back and fourth eg) CO2 on till you reach the desired ppm, switch off, fan then turns on. Set them up on timers and you wont have to worry. Another thing, C02, in my belief, is more benficial during your blooming cycle. As well, generating CO2 for 12 hrs constantly is a VERY LONG time. Heat will be a definite issue for you. Ideally,an optimal temp for most breeds during the light cycle is around 78 degrees, and below 70 with the lights off.
I have read from some sources that plants desire a temp between 85-95 degrees with co2 or they cannot efficiently absorb the co2 and put it to use for photosynthesis. The leaves seem to be getting very large and I don't seem to see any stress on the plants.
from page 332 of"marijuana horticultre the indoor/outdoor medical growers bible"by jorge cervantes,2006 cannabis regulates its oxygen uptake in relationship to the ambient air tempature rather than the available amont of oxygen...tempertatures above 85*f(29*c)are not recomended even when using co2 enrichment.page 337-a high temp from 75*-85*F will stimulate more rapid metabolism within the co2 enriched plants,when tempatures climb beyond 85*F co2 enrichment becomes ineffective,and at 90*F growth stops... ////yet ive grown some good crops when the temperatures were above 100-110,but i was watering at least once a day in five gallon buckets.but the winter crops of the same clone genectics were twice as heavy and oh the purples during the cold season,even the taste was more intense.i keep temps in controll these days...
I don't care what Jorge says/thinks. I've grown at hot temps with and without. With CO2 was always better.
